Electrostatic chuck filter box and mounting bracket

ABSTRACT

An apparatus and method electrically coupling an electrostatic chuck RF filter box with a pedestal lift. The RF filter box has a contact block and at least one alignment feature on an outer mating surface of the RF filter block. The contact block includes self-aligning electrical connectors and the alignment feature is configured for aligning self-aligning electrical connectors with corresponding electrical connectors on the bracket of the pedestal lift such that the self-aligning electrical connectors and the corresponding electrical connectors on the bracket of the pedestal lift automatically mate when the contact block is mounted to the bracket of the pedestal lift.

BACKGROUND

The disclosure relates to a method and apparatus for semiconductorprocessing. More specifically, the disclosure relates to anelectrostatic chuck filter box and mounting bracket for filtering RFsignals from other signals.

Semiconductor processing systems, which are used to process substratessuch as semiconductor wafers, typically include a substrate support,such as a chuck, for holding a wafer during semiconductor processing.One type of chuck is an electrostatic chuck (ESC), which includes aplaten having electrodes that are biased with voltage to produce anelectrostatic force between the wafer and platen in order to hold thewafer to the platen. Typically, DC signals are used to control thevoltage power supplies for controlling the clamping and de-clampingfunctions of the ESC.

A radio frequency (RF) filter box is an electromechanical assembly thatfilters RF signals from other signals, such as sensitive DC signals(from ESC clamping voltage) and AC signals (from the ESC heater).Typically, an RF filter box is electrically coupled with the ESCpedestal lift and uses manual connectors to make each electricalconnection separately. The RF filter box must first be mounted to thepedestal lift. Panels on the RF filter box can then be removed to gainaccess to these manual electrical connections. Manually making theseelectrical connections requires manipulation of the connecting wires andcan be difficult and may not always be consistent. Consistent placementof the wires is critical to the performance of the filtering circuits.Thus, there is a need for an ESC RF filter box that provides a reliableand consistent way to make automatic electrical and mechanicalconnections.

SUMMARY

According to an embodiment, an electrostatic chuck RF filter box isprovided for mounting on a bracket of a pedestal lift to make aplurality of electrical connections. The RF filter box includes at leastone contact block and at least one alignment feature. The contact blockincludes a plurality of self-aligning electrical connectors on a matingsurface of the RF filter block. The mating surface is an outer surfaceof the RF filter box. The alignment feature is on the mating surface ofthe RF filter box, and is configured for aligning the self-aligningelectrical connectors with corresponding electrical connectors on thebracket of the pedestal lift such that the self-aligning electricalconnectors and the corresponding electrical connector on the bracket ofthe pedestal lift automatically mate when the contact block is mountedto the bracket of the pedestal lift.

According to another embodiment, a method is provided for electricallycoupling an electrostatic chuck RF filter box with a pedestal lift. Anelectrostatic chuck RF filter box is provided. The filter box includesat least one contact block and at least one alignment feature. Thecontact block includes a plurality of self-aligning electricalconnectors on an outer mating surface of the RF filter block and thealignment feature is on the outer mating surface of the RF filter box.The alignment feature is configured for aligning the self-aligningelectrical connectors with corresponding electrical connectors on thebracket of the pedestal lift such that the self-aligning electricalconnectors and the corresponding electrical connectors on the bracket ofthe pedestal lift automatically mate when the contact block is mountedto the bracket of the pedestal lift. The outer mating surface of the RFfilter box is then positioned against a mating surface of a mountingbracket of the pedestal lift by using the at least one alignment featureto engage a corresponding alignment feature on the mounting bracket ofthe pedestal lift. The RF filter box is then secured to the mountingbracket of the pedestal lift to electrically couple the RF filter boxwith the pedestal lift, where the plurality of electrical connectors onthe RF filter box and the corresponding electrical connectors on thebracket of the pedestal lift automatically mate when the RF filter boxis mounted to the pedestal lift.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 is a perspective view of the front side of a RF filter box inaccordance with an embodiment.

FIG. 2 is an exploded view of the RF filter box shown in FIG. 1.

FIG. 3 is a perspective view the back side of the RF filter box shown inFIGS. 1 and 2.

FIG. 4 is perspective view the bottom side of the RF filter box shown inFIGS. 1-3.

FIG. 5A is a detailed view of an embodiment of a contact block andelectrical sockets in the mounting bracket of a RF filter box.

FIG. 5B is a detailed view of one of the electrical sockets shown inFIG. 5A and a corresponding pin.

FIG. 6 is a perspective view of the mating side of a mounting bracket onthe pedestal lift in accordance with an embodiment.

FIG. 7A is a detailed exploded view of contact blocks and electricalsockets and pins for RF signals in accordance with an embodiment.

FIG. 7B is a detailed perspective view of the contact blocks andelectrical sockets and pins for RF signals shown in FIG. 7A.

FIG. 8A is a detailed exploded view of contact blocks and electricalsockets and pins for AC signals in accordance with an embodiment.

FIG. 8B is a detailed perspective view of the contact blocks andelectrical sockets and pins for AC signals shown in FIG. 8A.

FIG. 9 is a flow chart of a method of electrically coupling anelectrostatic chuck RF filter box with a pedestal lift in accordancewith an embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will now be described in detail with reference toa few preferred embodiments thereof as illustrated in the accompanyingdrawings. In the following description, numerous specific details areset forth in order to provide a thorough understanding of the presentinvention. It will be apparent, however, to one skilled in the art, thatthe present invention may be practiced without some or all of thesespecific details. In other instances, well known process steps and/orstructures have not been described in detail in order to notunnecessarily obscure the present invention.

With reference to FIGS. 1-9, embodiments of a RF filter box 100 aredescribed. The RF filter box 100 is an electromechanical assembly formounting on a bracket of a pedestal lift 610 of an ESC to makeelectrical connections. According to some embodiments, the pedestal lift610 can be moving. The RF filter box 100 filters RF signals from othersignals, such as sensitive DC signals (from ESC clamping) and AC signals(from the heater of the ESC). As described in more detail herein,according to an embodiment, the mechanical portion of the RF filter box100 employs sockets that are set into custom contact blocks. Thesesockets are then mated to pins located on the mounting bracket of thepedestal lift assembly to make an automatic electrical connection forthe RF, AC, and DC signals. As discussed in more detail below, alignmentpins on the RF filter box 100 can be used to help make the matingconstituent and reliable. Accurate and repeatable placement of theelectrical connections ensure the integrity and reliability of the RF,AC, and DC signals.

FIGS. 1-4 show an embodiment of a RF filter box 100 that is configuredto be mounted to an ESC pedestal lift mounting bracket (FIG. 6). Asshown in FIGS. 1-4, the RF filter box 100 has an enclosure 110 in whichwires and other components are housed. The enclosure 110 is closed withan enclosure cover 120 on the front side, as shown in FIGS. 1 and 2. Onthe back side of the RF filter box 100, as shown in FIG. 3, is thefilter box mounting bracket 112. This mounting bracket 112 allows the RFfilter box 100 to be mounted to the mounting bracket 600 (FIG. 6) of thepedestal lift 610. The outer surface of the RF filter box 100 includesthe enclosure 110, the enclosure cover 120, and the mounting bracket112. In the illustrated embodiment, the RF filter box 100 also includesseveral fan assemblies, including the ESC/high frequency (HF) filter fanassembly 130, the low frequency (LF) filter fan assembly 140, and thefan sense assembly 150.

As shown in FIGS. 1-4, an AC connector 160 is provided on the RF filterbox to receive the AC signals from the heater lines. FIG. 2 is anexploded view of the RF filter box 100 and shows components within theRF filter box 100, including a ESC DC printed circuit board assembly(PCBA) 162, a low frequency RF PCBA 164 for low frequency input, andhigh frequency RF PCBA 166 for high frequency input. FIG. 4 shows abottom view of the RF filter box 100 with the AC connector 160, a RFconnector 168, and a DC connector 169.

To electrically connect the RF filter box 100 with the pedestal lift610, the mounting bracket 112 on the back side (mating surface) of theRF filter box 100 is configured to align with and be mounted to amounting bracket 600 (FIG. 6) on the pedestal lift 610. As shown in FIG.3, features that help with alignment are provided on the mating surfaceof the mounting bracket 112. These alignment features include aself-aligning AC connector 170 for AC heater lines, a self-aligning RFconnector 172 for RF inputs, a mounting keyway hole 174, a mountingalignment pin 176, and bracket mounting holes 178.

In the illustrated embodiment, a keyway insert 604 is provided to beinserted into and lock with the keyway hole 174 on the mounting bracket112 of the RF filter box 100. In this embodiment, a hole 606 is alsoprovided on the mating surface of the RF filter box 100, as shown inFIG. 3, to accept the corresponding alignment pin 176 on the mountingbracket 112 of the RF filter box 100. In other embodiments, the matingsurface of the mounting bracket 112 may have only one alignment feature,which may be one of an alignment pin, a hole, a keyway insert, and akeyway hole. It will be understood that any suitable alignment featuremay be used to align the two mounting brackets 112, 600. According toother embodiments, the mating surface of the mounting bracket 112 mayhave any number of such alignment features. The alignment features canbe provided in any combination, typically with a pin or protrusion onone mating surface (mounting bracket 112) configured to be mated with acorresponding indentation or hole on the other mating surface (mountingbracket 600). These alignment features can be any shape, ranging from asimple circular or cylindrical shape to a more complex shape, such as akeyway hole or the like.

It will be understood that such alignment features are configured to aidin aligning the self-aligning electrical connectors 171 on the mountingbracket 112 with corresponding electrical connectors 601 on the mountingbracket 600 of the pedestal lift 610 such that the self-aligningelectrical connectors 171 and the corresponding electrical connectors601 on the mounting bracket 600 of the pedestal lift 610 automaticallymate when the mounting brackets 112, 600 are aligned and their matingsurfaces are pushed together. These alignment features make theelectrical and mechanical connections between the RF filter box 100 andESC pedestal lift 610 as automatic and repeatable as possible. Thealignment features allow for electrical coupling without the need formanual manipulation of the connecting wires. Consistent placement of theconnecting wires is critical to the performance of the filteringcircuits.

The keyway hole 174 is configured to accept and lock with thecorresponding keyway insert 604 on the pedestal lift mounting bracket600. Similarly, the pin 176 on the mounting bracket 112 on the RF filterbox 100 is configured to be inserted into the corresponding hole 606 inthe mounting bracket 600 of the pedestal lift 610. In addition to thesealignment features, the mounting bracket 112 is also provided with aself-aligning AC connector 170 and a self-aligning RF connector 172.

Each of the self-aligning AC connector 170 and the self-aligning RFconnector 172 includes a contact block 173 having electrical connectors171 mounted therein. In the illustrated embodiment, the electricalconnectors 171 are sockets mounted in the contact blocks 173 and allowautomatic electrical connection to pins 601 on the pedestal liftmounting bracket 600 as the RF filter box 100 is mounted to the pedestallift assembly, which is capable of moving. It will be understood that,in other embodiments, the electrical connectors 171 on the mountingbracket can be pins while the electrical connectors 601 on the pedestallift mounting bracket 600 can be electrical sockets.

Each electrical socket 171 is configured to accept a corresponding pin601 on the pedestal lift mounting bracket 600 to make electricalconnections between the RF filter box 100 and the ESC pedestal lift 610.A suitable push-pull socket-pin connector is commercially available fromODU USA, Inc. of Camarillo, Calif. FIGS. 5A and 5B are detailed view ofsuch push-pull socket-pin connectors. FIG. 5A shows multiple electricalsockets 171 set in contact blocks 173. As shown in FIG. 5B, the socket171 has springwires 175 lining the inner surface of the socket 171 forcontact with a pin 601 when the pin 601 is inserted into the socket 171.

The contact blocks 173 on the mounting bracket 112 are formed of aninsulating material. According to an embodiment, the contact blocks 173are formed of Ultem1000 (UL94 V0), which is a type of amorphousthermoplastic polyetherimide (PEI) resin manufactured by SABIC (SaudiBasic Industries Corporation). Ultem 1000 has a high dielectric strengthand heat resistance. It will be understood that the insulating contactblocks 173 have electrical properties for voltage isolation and that thecontact blocks 173 can be designed to allow close pin to pin alignmentwhile providing separation for electrical isolation.

In the illustrated embodiment, the self-aligning AC connector 170 andthe self-aligning RF connector 172 allow for automatic electricalconnection of 3 RF signals and 4 AC signals between the RF filter box100 and the pedestal lift assembly. It will be understood that, in otherembodiments, there may be different numbers of RF and AC signals.

As shown in FIG. 6, the mounting bracket 600 on the pedestal lift 610 isconfigured to mate with the mounting bracket 112 (mating surface) of theRF filter box 100. The mounting bracket 112 of the RF filter box 100 canbe secured to the mounting bracket 600 on the pedestal lift 610 usingscrews (not shown) threaded through the bracket mounting holes 178 ofthe mounting bracket 112 of the RF filter box 100 and the correspondingbracket mounting holes 608 of the pedestal lift mounting bracket 600.

In the illustrated embodiment, the contact blocks 673 and electricalpins 601 on the pedestal lift mounting bracket 600 are positioned tomate with the corresponding contact blocks 173 and sockets 171 on themounting bracket 112 on the RF filter box 100 when the two mountingbrackets 112, 600 are aligned. As discussed above, alignment features onthe mounting brackets aid in alignment and the electrical sockets 171are configured to automatically electrically couple with thecorresponding pins 601 when the mounting brackets 112, 600 are pushedtogether after being aligned.

In this embodiment, the mounting bracket 600 is also provided with asnap-in dielectric mounting plate 602 for isolating electricalconnections from ground plane and metal walls. As shown in FIG. 6, thecontact blocks 673 are mounted in the mounting plate 602. According toan embodiment, the mounting plate 602 is formed of Ultem and nylonfasteners hold the mounting plate 602 to the mounting bracket 600.

FIGS. 7A and 7B are detailed views of an embodiment of contact blocksand electrical sockets and pins for RF signals, and FIGS. 8A and 8B aredetailed views of an embodiment of contact blocks and electrical socketsand pins for AC signals. FIGS. 7B and 8B show the contact blocks andelectrical connectors in the mated position. As shown in FIG. 7A-8B, inthis embodiment, the electrical sockets 171 are mounted in a contactblock 173.

Similarly, the pins 601 are mounted in a contact block 673. In thisembodiment, the contact block 673 comprises two parts 673A, 673B toallow the pins 601 to be replaced even after installation. That is, therear portion of the contact block 673 is installed on the mounting block600 of the pedestal lift 610, and the pins 601 are inserted into therear portion 673B. The front portion 673A is then attached to the rearportion 673B after the pins 601 are positioned in place. Thus, if a pin601 need to be replaced, the front portion 673A can be removed withoutremoving the entire assembly from the pedestal lift mounting block 600.

The contact blocks 173, 673 are fastened to the mounting brackets 112,600 by fasteners formed of insulating material, such as nylon. As shownin FIGS. 7A-8B, the contact blocks 173, 673 are fastened to the mountingblocks 112, 600 by a plurality of fasteners, including a nylon standoff177A, a nylon washer 177B, and a nylon cap screw 177C. It will beunderstood that the self-alignment of the contact blocks 173, 673 allowsome float to account for position differences of the mating side.Slightly enlarged holes and the standoffs 177A allow the contact blocks173, 673 to float.

FIG. 9 is a flow chart of a method 900 of electrically coupling anelectrostatic chuck RF filter box with a pedestal lift. In Step 910, anESC RF filter box is provided. The RF filter box includes at least onecontact block and at least one alignment feature on the outer matingsurface of the RF filter box. The contact block(s) include a pluralityof self-aligning electrical connectors on an outer mating surface of theRF filter block and the at least one alignment feature is configured foraligning the self-aligning electrical connectors with correspondingelectrical connectors on the bracket of the pedestal lift such that theself-aligning electrical connectors and the corresponding electricalconnectors on the bracket of the pedestal lift automatically mate whenthe contact block is mounted to the bracket of the pedestal lift. InStep 920, the outer mating surface of the RF filter box is positionedagainst a mating surface of a mounting bracket of the pedestal lift byusing the at least one alignment feature to engage a correspondingalignment feature on the mounting bracket of the pedestal lift. In Step930, the RF filter box is secured to the mounting bracket of thepedestal lift to electrically couple the RF filter box with the pedestallift, where the plurality of electrical connectors on the RF filter boxand the corresponding electrical connectors on the bracket of thepedestal lift automatically mate when the RF filter box is secured tothe mounting bracket of the pedestal lift.

What is claimed is:
 1. An electrostatic chuck RF filter box for mountingon a bracket of a pedestal lift to make a plurality of electricalconnections, the RF filter box comprising: at least one contact blockincluding a plurality of self-aligning electrical connectors on a matingsurface of the RF filter block, wherein the mating surface is an outersurface of the RF filter box; and at least one alignment feature on themating surface of the RF filter box, wherein the at least one alignmentfeature is configured for aligning the self-aligning electricalconnectors with corresponding electrical connectors on the bracket ofthe pedestal lift such that the self-aligning electrical connectors andthe corresponding electrical connector on the bracket of the pedestallift automatically mate when the contact block is mounted to the bracketof the pedestal lift.
 2. The electrostatic chuck RF filter box asrecited in claim 1, comprising at least two contact blocks, wherein afirst contact block is configured to filter RF signals and a secondcontact block is configured to filter AC signals.
 3. The electrostaticchuck RF filter box as recited in claim 2, wherein the first contactblock is configured to filter at least three RF signals and the secondcontact block is configured to filter at least four AC signals.
 4. Theelectrostatic chuck RF filter box as recited in claim 1, wherein the RFfilter box filters low frequency and high frequency RF signals.
 5. Theelectrostatic chuck RF filter box as recited in claim 1, wherein the RFfilter box filters AC heater signals.
 6. The electrostatic chuck RFfilter box as recited in claim 1, wherein the RF filter box filters DCclamping voltage.
 7. The electrostatic chuck RF filter box as recited inclaim 1, further comprising at least one fan assembly.
 8. Theelectrostatic chuck RF filter box as recited in claim 1, comprising atleast two alignment features on the mating surface.
 9. The electrostaticchuck RF filter box as recited in claim 8, wherein the at least twoalignment features comprise an alignment pin and a keyway hole.
 10. Theelectrostatic chuck RF filter box as recited in claim 8, wherein the atleast two alignment features comprise at least two alignment pins. 11.The electrostatic chuck RF filter box as recited in claim 8, wherein theat least two alignment features comprise at least two keyway holes. 12.The electrostatic chuck RF filter box as recited in claim 1, wherein thepedestal lift is movable.
 13. The electrostatic chuck RF filter box asrecited in claim 1, wherein the at least one contact block is formed ofan insulating material.
 14. The electrostatic chuck RF filter box asrecited in claim 1, wherein the at least one contact block is fastenedto an enclosure of the RF filter box by a fasteners formed of insulatingmaterial.
 15. A method of electrically coupling an electrostatic chuckRF filter box with a pedestal lift, the method comprising: providing theelectrostatic chuck RF filter box, wherein the RF filter box comprises:at least one contact block including a plurality of self-aligningelectrical connectors on an outer mating surface of the RF filter block;and at least one alignment feature on the outer mating surface of the RFfilter box, wherein the at least one alignment feature is configured foraligning the self-aligning electrical connectors with correspondingelectrical connectors on the bracket of the pedestal lift such that theself-aligning electrical connectors and the corresponding electricalconnectors on the bracket of the pedestal lift automatically mate whenthe contact block is mounted to the bracket of the pedestal lift;positioning the outer mating surface of the RF filter box against amating surface of a mounting bracket of the pedestal lift by using theat least one alignment feature to engage a corresponding alignmentfeature on the mounting bracket of the pedestal lift; and securing theRF filter box to the mounting bracket of the pedestal lift toelectrically couple the RF filter box with the pedestal lift, whereinthe plurality of electrical connectors on the RF filter box and thecorresponding electrical connectors on the bracket of the pedestal liftautomatically mate when the RF filter box is secured to the mountingbracket of the pedestal lift.
 16. The method as recited in claim 15,wherein the RF filter box comprises at least two contact blocks, whereina first contact block is configured to filter RF signals and a secondcontact block is configured to filter AC signals.
 17. The method asrecited in claim 16, wherein the first contact block is configured tofilter at least three RF signals and the second contact block isconfigured to filter at least four AC signals.
 18. The method as recitedin claim 15, wherein the RF filter box filters low frequency and highfrequency RF signals.
 19. The method as recited in claim 15, wherein theRF filter box filters AC heater signals.
 20. The method as recited inclaim 15, wherein the RF filter box filters DC clamping voltage.
 21. Themethod as recited in claim 15, wherein the RF filter box comprises atleast two alignment features on the mating surface.
 22. The method asrecited in claim 21, further comprising: aligning an alignment pin onthe mating surface with a keyway hole on the bracket of the pedestallift; and aligning a keyway hole on the mating surface with an alignmentpin on the bracket of the pedestal lift.
 23. The method as recited inclaim 21, further comprising aligning at least two alignment pins withtwo corresponding keyway holes on the bracket of the pedestal lift. 24.The method as recited in claim 21, further comprising aligning at leasttwo keyway holes with two corresponding alignment pins on the bracket ofthe pedestal lift.
 25. The electrostatic chuck RF filter box as recitedin claim 1, wherein the pedestal lift is movable.
 26. The electrostaticchuck RF filter box as recited in claim 1, wherein the at least onecontact block is formed of an insulating material.
 27. The electrostaticchuck RF filter box as recited in claim 1, wherein the at least onecontact block is fastened to an enclosure of the RF filter box by afastener formed of insulating material.